Electrical test block



C. A. MILBANK ELECTRICAL TEST BLOCK Filed Jan. 11. 1949 I N VHV TOR.

' Chqvles A.Mc'u ank Patented Oct. 17, 1950 UNITED STATES PATENT OFFICE 2,526,255, ELECTRICAL 'PEST BLOCK I Charles A. Milbank, Kansas City, Mo. Application January 11, 1949, Serial No. 70,345

.be determined without interrupting the current supply to the point of use.

Another object is to produce a device of this character whereby a meter may be lay-passed or removed from the line for any purpose without interrupting the current to the point ofusep A further object of the invention is to produce a test block of this kind which is strong, durable, convenient and may be insulated by barriers to-prevent arcing between terminals of opposite polarity and to guard against accidental short .circuiting by pliers, wrenches, or the like.

A still further object of the invention is to provide a unit test block, together with means for assembling a plurality of the blocks for as many circuits as desired, eachblock being separated from adjacent blocks by an insulating barner.

With the general object named in view and others as will hereinafter appear, the invention consists in certain novel and useful features of construction and organization of parts as hereinafter described and claimed; and in order that it may be fully understood, reference is to be had to the accompanying drawing, in which- Figure 1 is a top plan view of a unit test block embodying the invention.

Figure 2 is a bottom plan view of the same.

Figure 3 is a section on the line I-IIIII of Figure 1.

Figure 4 is a side elevation of the device, taken at right angles to the plane of the section shown in Figure 3.

Figure 5 is a perspective view of a multiple installation in exploded position to showthe in coincidental relationship tothe four corners of i.

the block, said openings 2 being countersunk as at 3 from the under face or bottom of the block.

In addition to the openings 2, the block is formed with a pair of through openings 4 0n the eerie ter line of the block paralleling that of the four 1 Claim. (01. 1 3424) openings 2.

2 ,The openings 4 are countersunk from the top face of the block as indicated at 5. The top face of the block is molded or formed witha pair 'of parallel grooves 6, each groove intersecting perpendicularly the axes of the openings Land at their midpoint a pair of nut-receiving sockets I are formed in the upper face of the block, said sockets opening into the rooves 6.

Adapted, to be snugly received within the,

grooves 6 are four terminals of anysuitable type,

but for convenience of illustration are, shown as identical, the proximate ends or tangs of each pair being spaced apart and are notched or have a radius '9 for a, purpose which hereinafter ap pears. The outer ends of the connectors may be formed with rectangular chambers l0 adapted to receive line wires held in position by clamp Screw l l tapped through the top wall of the members Ill, or any other suitable terminals may be used if desired. Fitted within the-grooves 6 and underlying the tangs 8 are insulatingstrips l2 having openings registering with the openings 2 "and being provided at their midpoint with upstanding insulating sleeves l3 which fit into the radii in the ends of the tangs as indicated at 9, Figure 1.

The connector tangs 8 are positioned on top of the insulating strips [2 and are held rigidly in place by screws I4 inserted through the bottom face of the insulating block through the openings 2, and are used todraw the assembly, connectors and insulating strips, tightly down in the grooves 6. With the parts in the relation described circuits have not yet been completed through the connectors.

Circuits through the tanks 8 are completed by positioning a threaded nut IS in non-rotatable relation in the sockets or cavities 1, it being noted in this .connneotion that the insulating strips [2 prevent the nuts Hi from accidentally completing a circuit through the spaced tangs and at the same time guard against any tendency of the tangs to be bent or inclined when the circuit is completed as will hereinafter appear. The circuit through the tangs 8 is completed by a clamp screw ll having a circuit completing washer [8, which is preferably of copper,

staked or otherwisennonrotatably secured to the clamp screws, said'screw extending through the sleeve l3 and being engaged with the nut 16. Obviously when a circuit is to be broken the screws and their washers can be loosened or backed away from contact with tangs 8, in a convenient and expeditious manner without handling a multiplicity of parts. If desired a pair of clamp screws II may be tapped to receive small clamp screws l5 for supporting circuit jumpers when a meter is to be by-passed or removed for repair or replacement.

In order that a plurality of the unit test blocks may be assembled as a panel, each set of blocks being partitioned from adjacent blocks so that there is no danger of arcing between terminals of opposite polarity or accidental shorting by tools or the like, each of said blocks is formed in a pair of its opposite lower edges with recesses or chambers l9. Insulating barriers 20 are adapted to be interposed between adjacent unit blocks, said barriers being of considerable height and being formed with oppositely projecting lugs 2| to be received within the recesses IQ of a pair of adjacent blocks, see Figure 5. With this arrangement any number of units may be built up, each unit being held to a base or support by mounting screws (not shown) engaged with the openings 4 in the blocks. In Figures 6 and 7 a slightly modified barrier is shown at 22, such barrier having a pair of lugs or dowels 23 projecting from its opposite faces.

From the above description it will be apparent that I have produced an electrical test block embodying all of the features of advantage set forth as desirable, and while I have described and illustrated the preferred construction, it is to be understood that I reserve the right to all changes within the spirit and scope of the appended claim.

I claim:

A test block comprising a rectangular insulating base having a pair of parallel grooves in its upper face and recesses in its lower face, a pair of insulating strips fitted in the grooves and having upstanding insulating sleeves at their midpoint, a pair of tangs resting on each strip within the grooves and having upstanding hollow rectangular terminals at their outer ends and having arcuate inner ends to accommodate the insulating sleeves, clamp bolts threaded through the top walls of the terminals, a second set of clamp bolts extending through the bottom of the block into threaded engagement with each tang and in coaxial relation to the first clamp bolts, and a connector for completing a circuit through the tangs, said connector comprising a bolt and nut combination, the latter being seated in a recess in the block and the former extending through the insulating sleeve and overlying and contacting the upper surfaces of the tangs.

CHARLES A. MILBANK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,788,567 Egger Jan. 13, 1931 2,064,736 Dahl Dec. 15, 1936 2,072,635 Helgason et al. Mar. 2, 1937 2,199,219 Edwards et al. Apr. 30, 1940 2,210,418 Larson Aug. 8, 1940 2,368,505 Weldon Jan. 30, 1945 FOREIGN PATENTS Number Country Date 608,287 Germany Dec. 27, 1934 670,944 France Dec. 6, 1929 787,887 France Sept. 30, 1935 

